US20050168102A1 - Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator - Google Patents

Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator Download PDF

Info

Publication number
US20050168102A1
US20050168102A1 US10/909,335 US90933504A US2005168102A1 US 20050168102 A1 US20050168102 A1 US 20050168102A1 US 90933504 A US90933504 A US 90933504A US 2005168102 A1 US2005168102 A1 US 2005168102A1
Authority
US
United States
Prior art keywords
underlayer
electrode layer
region
resonator
acoustic wave
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US10/909,335
Other languages
English (en)
Inventor
Hisanori Matsumoto
Kengo Asai
Atsushi Isobe
Mitsutaka Hikita
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Consumer Electronics Co Ltd
Original Assignee
Hitachi Media Electronics Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Media Electronics Co Ltd filed Critical Hitachi Media Electronics Co Ltd
Assigned to HITACHI MEDIA ELECTRONICS CO., LTD. reassignment HITACHI MEDIA ELECTRONICS CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HIKITA, MITSUTAKA, ISOBE, ATSUSHI, ASAI, KENGO, MATSUMOTO, HISANORI
Publication of US20050168102A1 publication Critical patent/US20050168102A1/en
Priority to US11/602,330 priority Critical patent/US7408287B2/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
    • H03H9/56—Monolithic crystal filters
    • H03H9/564—Monolithic crystal filters implemented with thin-film techniques
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
    • H03H3/04—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks for obtaining desired frequency or temperature coefficient
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
    • H03H9/02—Details
    • H03H9/02007—Details of bulk acoustic wave devices
    • H03H9/02157—Dimensional parameters, e.g. ratio between two dimension parameters, length, width or thickness
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
    • H03H9/15—Constructional features of resonators consisting of piezoelectric or electrostrictive material
    • H03H9/17—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator
    • H03H9/171—Constructional features of resonators consisting of piezoelectric or electrostrictive material having a single resonator implemented with thin-film techniques, i.e. of the film bulk acoustic resonator [FBAR] type
    • H03H9/172—Means for mounting on a substrate, i.e. means constituting the material interface confining the waves to a volume
    • H03H9/174—Membranes
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H9/00—Networks comprising electromechanical or electro-acoustic elements; Electromechanical resonators
    • H03H9/46—Filters
    • H03H9/54—Filters comprising resonators of piezoelectric or electrostrictive material
    • H03H9/56—Monolithic crystal filters
    • H03H9/566—Electric coupling means therefor
    • H03H9/568—Electric coupling means therefor consisting of a ladder configuration
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
    • H03H2003/023—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks the resonators or networks being of the membrane type
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
    • H03H3/04—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks for obtaining desired frequency or temperature coefficient
    • H03H2003/0414—Resonance frequency
    • H03H2003/0421—Modification of the thickness of an element
    • H03H2003/0442—Modification of the thickness of an element of a non-piezoelectric layer
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
    • H03H3/00—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators
    • H03H3/007—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks
    • H03H3/02—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks
    • H03H3/04—Apparatus or processes specially adapted for the manufacture of impedance networks, resonating circuits, resonators for the manufacture of electromechanical resonators or networks for the manufacture of piezoelectric or electrostrictive resonators or networks for obtaining desired frequency or temperature coefficient
    • H03H2003/0414—Resonance frequency
    • H03H2003/0471—Resonance frequency of a plurality of resonators at different frequencies

Definitions

  • the present invention relates to film bulk acoustic wave resonator filters employing film bulk acoustic wave resonators (hereinafter referred to as FBARs) and a manufacturing method thereof.
  • FBARs film bulk acoustic wave resonators
  • a filter that is constructed from FBARs has features of excellence in the following respects: (1) higher frequency operation, (2) smaller construction, (3) temperature characteristics, and (4) high voltage immunity.
  • a basic FBAR structure is as follows: a piezoelectric layer is sandwiched between a bottom electrode layer and a top electrode layer and an underlayer supports this sandwich over a cavity (for example, refer to non-patent document 1). By applying an electric signal between the two electrodes isolated by the piezoelectric layer, bulk acoustic waves are excited in the piezoelectric layer. At this time, the path of the bulk acoustic waves is a diaphragm structure consisting of the sandwich and the underlayer.
  • the top and bottom of the diaphragm structure are acoustically isolated by air, the bulk acoustic waves reflect from the interfaces between the diaphragm structure and the air, which prevents the acoustic energy from leaking out of the diaphragm structure.
  • the following improved FBAR structures are known: a structure in which a loading electrode is added to the bottom surface of the bottom electrode layer (for example, refer to patent document 1); a structure in which a loading layer is added to the surface of the piezoelectric layer (for example, refer to patent document 2); and a structure in which a loading electrode is added to the surface of the top electrode layer (for example, refer to patent document 3).
  • the FBAR is a device that converts electrical signals input thereto into mechanical vibration and resonates at a frequency that is in inverse proportion to the thickness of its diaphragm structure. Taking advantage of this property, the FBAR can be used as a radio frequency resonator in electronic circuitry.
  • a transmit/receive switching device with two filters, namely, a transmitting filter for transmitting frequency and a receiving filter for receiving frequency must be fabricated.
  • FBAR filters are required to be fabricated on a single substrate and, ultimately, fabricating the transmitting and receiving filters on the single substrate is hoped for.
  • the FBAR resonates at a frequency that is one half the wavelength of the total thickness of its diaphragm structure
  • its resonant frequency is clearly determined from the total thickness of its diaphragm structure, the acoustic velocities of the underlayer material, bottom electrode layer material, piezoelectric layer material, and top electrode layer material.
  • the resonant frequency of the FBAR can be controlled.
  • the FBAR device after forming the loading layer, the FBAR device must be removed from vacuum equipment for patterning the loading layer in air environment. Consequently, the loading layer surface is oxidized, which causes deteriorating the resonance characteristics. Because of the additional process of patterning the loading layer, the number of times the device is exposed to a photoresist material, developer, etching liquid or gas, etc. increases. As a result, factors to degrade the film quality of the sandwich significantly increase, which leads to deteriorating the resonance characteristics.
  • FIG. 12 shows an FBAR equivalent circuit.
  • R 1 is loss of the bottom electrode layer
  • R 2 is loss of the piezoelectric layer
  • R 3 is loss of the top electrode layer.
  • the FBAR filter To construct the FBAR filter, it is required to make a plurality of FBARs resonate at different resonant frequencies and to prevent the factors to decrease the quality, especially, the Q factor of the sandwich that is the main FBAR portion from being introduced during its fabrication.
  • An object of the present invention is to provide an FBAR filter having a structure that prevents the FBAR performance, especially, the Q factor, from decreasing, and a method of manufacturing the FBAR filter.
  • a film bulk acoustic wave resonator according to the present invention comprises a substrate having a cavity, an underlayer formed on the substrate to cover the cavity, a bottom electrode layer formed on top of the underlayer, a piezoelectric layer formed on top of the bottom electrode layer, and a top electrode layer formed on top of the piezoelectric layer, characterized in that its resonant frequency can be adjusted, depending on the thickness of the underlayer over the cavity.
  • FIG. 1 is a cross sectional diagram of an FBAR device as a first embodiment of the present invention.
  • FIG. 2 is a cross sectional diagram set to explain an exemplary procedure of fabricating the FBAR device shown in FIG. 1 in process sequence.
  • FIG. 3 is a cross sectional diagram of an FBAR device as a second embodiment of the present invention.
  • FIG. 4 is a cross sectional-diagram set to explain an exemplary procedure of fabricating the FBAR device shown in FIG. 3 in process sequence.
  • FIG. 5 is a circuit block diagram of a general mobile phone's front end portion.
  • FIG. 6 is a circuit block diagram of a sub-portion comprising a couple of transmitting and receiving filters constructed with an array of FBARs in the front end portion shown in FIG. 5 .
  • FIG. 7 is an external perspective view schematic of the transmitting filter made up of FBARs of the present invention, fabricated on a single substrate.
  • FIG. 8 is a cross sectional view of FBARs as an example of application of the FBAR structure of Embodiment 1.
  • FIG. 9 is a cross sectional view of FBARs as an example of application of the FBAR structure of Embodiment 2.
  • FIG. 10 is a cross sectional view of four FBARs to which the FBAR structure of Embodiment 1 is applied, the four FBARs constituting the couple of transmitting and receiving filters on the single substrate.
  • FIG. 11 is a cross sectional view of four FBARs to which the FBAR structure of Embodiment 2 is applied, the four FBARs constituting the couple of transmitting and receiving filters on the single substrate.
  • FIG. 12 is an FBAR equivalent circuit diagram.
  • FIG. 1 is a cross sectional diagram of an FBAR device which is one example f embodiment of the present invention.
  • a region where a first FBAR 11 is formed will be called a first region and a region where a second FBAR 12 is formed will be called a second region.
  • the first and second FBARs have their diaphragm structures which are respectively formed over cavities 9 and 10 formed on the back side of a single substrate.
  • the diaphragm structure in the first region comprises an underlayer 2 , bottom electrode layer 3 , piezoelectric layer 5 , and top electrode layer 7 .
  • the diaphragm structure in the second region comprises an underlayer 131 , bottom electrode layer 4 , piezoelectric layer 6 , and top electrode layer 8 .
  • the thickness t2 of the underlayer 131 of the diaphragm structure in the second region is thicker than the thickness t1 of the underlayer 2 of the diaphragm structure in the first region. Therefore, the thickness T2 of the diaphragm structure including the underlayer 131 in the second region is thicker than the thickness T1 of the diaphragm structure including the underlayer 2 in the first region. As a result, the resonant frequency of the second FBAR 12 is lower than the resonant frequency of the first FBAR 11 .
  • a preferable material of the piezoelectric layers 5 and 6 is aluminum nitride (AlN).
  • the area of the underlayer 131 over the cavity 10 should be equal to or larger than a section where the bottom electrode layer 4 and the top electrode layer 8 are formed and a complete match between the above area and the above section is not required. This is also true for the first region over the cavity 9 .
  • the FBARs with two different resonant frequencies formed on the single substrate are shown in FIG. 1 , it is also possible to form FBARs with three or more different resonant frequencies on the single substrate in the same way.
  • its resonant frequency depends on the diaphragm thickness including the underlayer.
  • the underlayer thickness can be changed without affecting the main sandwich structures and, thus, the FBARs with different frequencies can easily be constructed on the same chip.
  • FIG. 2 is a cross sectional diagram set to explain a procedure of fabricating the FBAR structure shown in FIG. 1 in process sequence.
  • f1 and f2 f1>f2
  • f1 1.9 GHz
  • the thickness T1 of the diaphragm structure consisting of the sandwich and underlayer, which resonates at the higher resonant frequency f1 out of the above set resonant frequencies is 1800 nm
  • the thickness of T2 of the diaphragm structure, which resonates at the lower resonant frequency f2 is 1950 nm.
  • a trench 69 with a depth of ⁇ t (100 nm) on the surface of the substrate 1 in the second region (see diagrams A and B in FIG. 2 ).
  • first top electrode layer 7 on top of the piezoelectric layer 5 in the first region by patterning and form the second top electrode layer 8 on top of the piezoelectric layer 6 in the second region (see diagram G in FIG. 2 ).
  • the underlayers with different thicknesses are formed without affecting the main sandwich structures and, consequently, the diaphragm structures with different thicknesses can be achieved.
  • the FBARs with different resonant frequencies can easily be constructed on the single substrate.
  • Depositing the bottom and top electrode layers is normally performed by sputtering and the piezoelectric layer can be grown by sputtering or chemical vapor deposition (CVD).
  • CVD chemical vapor deposition
  • Patterning the layers can be performed by wet or dry etching.
  • the trench 69 can be formed by GCIB; otherwise, it can be formed by using other techniques such as dry etching, wet etching, and ion milling. Smoothing to make the underlayer 2 surface in the first region flush with the underlayer 131 surface in the second region can be performed by chemical mechanical polishing (CMP) besides GCIB.
  • CMP chemical mechanical polishing
  • dry or wet etching can be used.
  • Mo and W are materials of a high acoustic velocity, they have superior acoustic wave transmission properties. Another advantage of Mo and W is that they are easy to process by wet etch patterning. Other materials such as aluminum (Al), tantalum (Ta), nickel (Ni), niobium (Nb), gold (Au), platinum (Pt), cupper (Cu), palladium (Pd), titanium (Ti), and alloys thereof can be used as the material of the bottom and top electrode layers.
  • any material may be selected from the following: silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), alumina (Al 2 O 3 ), AlN, and silicon carbide (SiC). Because the underlayers must support the sandwiches with hollows being under them, it is desirable that they have a high mechanical strength. In this respect, SiO 2 , Si 3 N 4 , Al 2 O 3 , AlN, and SiC are preferable. Other materials such as zinc oxide (ZnO), lead zirconate titanate (PZT), lead titanate (PbTiO 3 ), and barium titanate (BaTiO 3 ) can be used as the material of the underlayers.
  • the material of the piezoelectric layers besides AlN, ZnO, PZT, PbTiO 3 , and BaTiO 3 can be used.
  • the aforementioned thicknesses of the layers are exemplary and, needless to say, can be designed and changed, as appropriate, according to employed materials and required resonant frequencies.
  • the diaphragm structures of the present FBARs can be fabricated to have thickness in the range of 300 nm to 7 ⁇ m in the state of the art of fabrication and this technology is applicable for resonant frequencies of 0.5 GHz to the order of 10 GHz.
  • FIG. 3 is a cross sectional diagram of an FBAR device which is another example of embodiment of the present invention.
  • a region where a first FBAR 23 is formed will be called a first region and a region where a second FBAR 24 is formed will be called a second region.
  • the same case as for Embodiment 1 is also discussed herein; that is, the resonant frequencies of the FBARs are 1.9 GHz and 0.1.75 GHz, respectively, and AlN is used as the piezoelectric layer material. Therefore, the required thickness T1 of the diaphragm structure in the first region and the required thickness T2 of the diaphragm structure in the second region are the same as for Embodiment 1.
  • the first FBAR 23 and second FBAR 24 are formed on the single substrate, on the back side of which cavities 21 and 23 are formed thereunder, respectively.
  • the thickness t1 of the underlayer 14 of the diaphragm structure in the first region is thinner than the thickness t2 of the underlayer of the diaphragm structure in the second region.
  • the resonant frequency f1 of the first FBAR 23 is higher than the resonant frequency f2 of the second FBAR 24 .
  • the area of the thinner underlayer 14 over the cavity 21 in the first region should be equal to or larger than a section where a bottom electrode layer 15 and top electrode layer 19 are formed in the first region and a complete match between the above area and the above section is not required. This is also true for the second region over the cavity 22 .
  • FIG. 4 is a cross sectional diagram set to explain a procedure of fabricating the FBAR structure shown in FIG. 3 in process sequence.
  • the trench 70 can be formed by wet etching, dry etching, ion milling, and GCIB.
  • Embodiment 2 The fabrication procedure of Embodiment 2 is advantageous in that it dispenses with smoothing by GCIB and, accordingly, the FBAR device is constructed with a reduced number of processes as compared with Embodiment 1.
  • the trench 70 in the underlayer can also be formed in the following method: after completely removing the underlayer in the region where the trench is to be formed until the substrate 13 surface is exposed, deposit the underlayer material over the surface again. This method neutralizes the effect of reducing the number of processes. However, its merit is that the underlayer can be formed to a thickness that is more accurate than in the case of forming the trench 70 by trenching.
  • This section describes constructing a filter with FBARs on a single substrate as a third embodiment example of the invention.
  • FIG. 5 is a block diagram of a general mobile phone's front end portion.
  • reference numeral 130 denotes a phase shifter which enables an antenna to be shared by a receiving portion and a transmitting portion.
  • Radio frequency (RF) received signals Rx received by the antenna ANT pass through the phase shifter 130 and through a receiving filter 79 which removes image frequency signals and allows only signals falling within a predetermined frequency range of receiving bandwidth and input to a low noise amplifier 128 .
  • the RF received signals Rx amplified in the low noise amplifier 128 are passed to the mobile phone's internal circuitry comprising a mixer circuit, an intermediate frequency filter, etc. which are not shown.
  • RF transmitting frequency signals Tx which have been passed from the mobile phone's internal circuitry not shown are amplified by a power amplifier 129 and pass through a transmitting filter 48 which allows only signals falling within a predetermined frequency range of transmitting bandwidth, and, then, emitted as radio waves from the antenna.
  • the above transmitting filter 78 and the receiving filter 79 for RF signals, employed in the front end portion, can be constructed by an ensemble of a plurality of FBARs.
  • a FBAR filter consisting of a plurality of FBARs as the present embodiment, which is constructed as the transmitting filter 78 and the receiving filter 78 , will be explained.
  • the transmitting frequency Tx band ranges from 1.85 to 1.91 GHz and the receiving frequency Rx band ranges from 1.93 to 1.99 GHz.
  • FIG. 6 is a circuit block diagram of a sub-portion comprising the phase shifter 130 , transmitting filter 78 , and receiving filter 79 in the front end portion shown in FIG. 5 .
  • the transmitting filter 78 is made up of an array of FBARs 71 - 77 within an upper block marked off by a dotted line and the receiving filter 79 is made up of an array of FBARs 120 - 126 within a lower block marked off by a dotted line.
  • a block 80 marked off by a chain line in FIG. 6 it will be described later in an Embodiment 4 section.
  • FIG. 7 an external perspective view schematic of the transmitting filter 78 fabricated on a single substrate is shown in FIG. 7 .
  • quadrangular FBARs 71 - 77 are shown here, the shape of the FBARs is not limited to quadrangles.
  • the FBARs 71 - 73 are series resonators and the FBARs 74 - 77 are shunt resonators.
  • solid lines between the FBARs denote wiring leads that connect to the top electrodes of the FBARs and dotted line denote wiring leads that connect to the bottom electrodes of the FBARs.
  • a quadrangular region 100 is a piezoelectric layer.
  • Reference symbol P 1 denotes an input wiring pad to which transmit signals passed from the internal circuitry not shown are input.
  • This input wiring pad is connected to an input pad P 11 of the filter, which is connected to an FBAR 71 of the transmitting filter 78 , by a bonding wire BW, and further connected via FBARs 72 , 73 connected in series by electrode wiring to an output pad P 22 of the filter.
  • the output pad P 22 of the filter and a pad P 2 connected to the antenna which is not shown are connected by a bonding wire BW.
  • Wiring pads connected to the top-electrodes of FBARs 74 , 76 and wiring pads connected to the bottom electrodes of FBARs 75 , 77 are connected to ground pads which are not shown by bonding wires, respectively.
  • the transmitting filter 78 shown in the circuit diagram of FIG. 6 is formed on the single substrate.
  • FIG. 8 is a cross sectional view of the FBARs with regard to the section taken along A-A′ line shown in FIG. 7 , wherein the FBAR structure of Embodiment 1 is applied to the FBARs.
  • An FBAR 74 is a shunt resonator
  • FBAR 71 is a series resonator
  • an FBAR 75 is a shunt resonator.
  • the underlayers 83 in the regions of the FBARs 74 and 75 are thicker than the underlayer 314 of the FBAR 71 .
  • the resonant frequency of the FBARs 74 and 75 is lower than the resonant frequency of the FBAR 71 .
  • the thickness T1 of the diaphragm structure of the FBAR 71 which resonates at 1.9 GHz is 1800 nm and its underlayer thickness t1 is 50 nm.
  • the thickness T2 of the diaphragm structures of the FBARs 74 and 75 which resonate at 1.75 GHz is 1950 nm and their underlayer thickness t2 is 200 nm.
  • the FBAR filter employing these FBARs can achieve a high Q factor.
  • FIG. 9 is a cross sectional view of the FBARs with regard to the section taken along A-A′ line shown in FIG. 7 , wherein the FBAR structure of Embodiment 2 is applied to the FBARs.
  • the thickness t2 of the underlayers in the regions of the FBARs 74 and 75 is thicker than the thickness t1 of the underlayer 131 of the FBAR 71 .
  • the resonant frequency of the FBARs 74 and 75 is lower than the resonant frequency of the FBAR 71 .
  • Embodiment 4 is an embodiment of the invention in which both transmitting and receiving filters employing FBARs are fabricated on a single substrate.
  • the couple of transmitting and receiving filters included in the front end portion circuitry shown in FIG. 5 are fabricated on the single substrate. Therefore, although the same circuitry as shown in FIG. 6 applies, the couple 80 of the transmitting filter 78 made up of the FBARs 71 - 77 and the receiving filter 79 made up of the FBARs 120 - 126 in the block marked off by the chain line in FIG. 6 is formed on the single substrate 1 .
  • FIG. 10 shows a fabrication example in which four FBARs with different resonant frequencies are fabricated on a single substrate in accordance with the FBAR structure shown in Embodiment 1.
  • the electrode wirings between the FBARs are omitted, and this figure shows a cross sectional view of the four FBARs having different diaphragm structure thicknesses T1, T2, T3, and T4 including different underlayer thicknesses t1, t2, t3, and t4 over the cavities 39 , 49 , 41 , and 42 , respectively.
  • the receiving filter 79 and transmitting filter 78 are formed on the single substrate 1 .
  • Each of both filters comprises FBARs of diaphragm structures formed to at least two different thicknesses; that is, referring to FIG. 6 , the receiving filter 79 comprises the FBARs 120 - 122 as series resonators and the FBARs 123 - 126 as shunt resonators and the transmitting filter 78 comprises the FBARs 71 - 73 as series resonators and the FBARs 74 - 77 as shunt resonators.
  • the receiving filter 79 consisting of an FBAR as a series resonator 43 with the diaphragm thickness T1 and an FBAR as a shunt resonator 44 with the diaphragm thickness T2 and the transmitting filter 78 consisting of an FBAR as a series resonator 45 with the diaphragm thickness T3 and an FBAR as a shunt resonator 46 with the diaphragm thickness T4 on the single substrate 1 .
  • FIG. 11 shows a fabrication example in which four FBARs with different resonant frequencies are fabricated on the single substrate 1 in accordance with the FBAR structure shown in Embodiment 2. Components corresponding to those shown in FIG. 10 are assigned the same reference numerals and their detailed explanation is not repeated for convenience of explanation. Referring to FIG. 11 , it will be appreciated that the four FBARs with different thicknesses can be formed on the single substrate to constitute the receiving filter 79 and transmitting filter 78 in the same way as in the case of FIG. 10 . To fabricate this structure, for example, in the fabrication process diagrams of FIG.
  • the FBARs can be formed by adding a process of patterning by photolithography and dry etching which are repeated to form other underlayers to the required thicknesses t1, t2, and t3 in process C.
  • both the FBAR structures disclosed in Embodiments 1 and 2 may coexist on the substrate.
  • All FBARs fabricated on the single substrate are made capable of resonating at different frequencies by forming their underlayers to different thicknesses and, thus, there is no need to introduce an additional structure into the main sandwich structures of the FBARs. Therefore, the sandwich fabrication process is easier as compared with the aforementioned conventional structure.

Landscapes

  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)
US10/909,335 2004-02-04 2004-08-03 Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator Abandoned US20050168102A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US11/602,330 US7408287B2 (en) 2004-02-04 2006-11-21 Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2004027590A JP4625260B2 (ja) 2004-02-04 2004-02-04 薄膜バルク共振子の製造方法
JP2004-027590 2004-02-04

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US11/602,330 Division US7408287B2 (en) 2004-02-04 2006-11-21 Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator

Publications (1)

Publication Number Publication Date
US20050168102A1 true US20050168102A1 (en) 2005-08-04

Family

ID=34805884

Family Applications (2)

Application Number Title Priority Date Filing Date
US10/909,335 Abandoned US20050168102A1 (en) 2004-02-04 2004-08-03 Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator
US11/602,330 Expired - Fee Related US7408287B2 (en) 2004-02-04 2006-11-21 Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator

Family Applications After (1)

Application Number Title Priority Date Filing Date
US11/602,330 Expired - Fee Related US7408287B2 (en) 2004-02-04 2006-11-21 Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator

Country Status (2)

Country Link
US (2) US20050168102A1 (enrdf_load_stackoverflow)
JP (1) JP4625260B2 (enrdf_load_stackoverflow)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050099092A1 (en) * 2003-11-07 2005-05-12 Hiroyuki Nakamura Piezoelectric device, antenna duplexer, and method of manufacturing piezoelectric resonators used therefor
US20100052476A1 (en) * 2007-11-21 2010-03-04 Panasonic Corporation Piezoelectric filter and method for manufacturing the same
US20160339475A1 (en) * 2015-05-20 2016-11-24 uBeam Inc. Transducer array subdicing
CN109889174A (zh) * 2019-02-20 2019-06-14 中国科学院微电子研究所 一种谐振器及其制作方法
CN111082777A (zh) * 2019-12-31 2020-04-28 诺思(天津)微系统有限责任公司 底电极为空隙电极的体声波谐振器、滤波器及电子设备
CN111130486A (zh) * 2019-12-11 2020-05-08 北京汉天下微电子有限公司 一种薄膜体声波谐振器结构及其制造方法、滤波器以及双工器
CN111277240A (zh) * 2020-03-07 2020-06-12 中国电子科技集团公司第二十六研究所 一种薄膜体声波滤波器的膜层结构及其制备方法
CN111293101A (zh) * 2018-12-10 2020-06-16 新光电气工业株式会社 半导体封装
CN112601169A (zh) * 2020-12-15 2021-04-02 武汉大学 一种宽频带高灵敏度谐振式压电mems麦克风
CN112886940A (zh) * 2021-01-13 2021-06-01 武汉大学 一种易于集成的fbar滤波器
CN113612463A (zh) * 2021-06-30 2021-11-05 中国电子科技集团公司第十三研究所 阶梯型薄膜体声波谐振器滤波器及滤波器组件
CN114160399A (zh) * 2021-12-02 2022-03-11 中国科学院苏州纳米技术与纳米仿生研究所 同频异构的压电超声波换能器及其制备方法
WO2022052915A1 (zh) * 2020-09-09 2022-03-17 诺思(天津)微系统有限责任公司 滤波器组件及其制造方法、电子设备
US20220216854A1 (en) * 2019-09-27 2022-07-07 Murata Manufacturing Co., Ltd. Acoustic wave device
CN116248068A (zh) * 2022-09-28 2023-06-09 泰晶科技股份有限公司 一种超高频at切石英晶片及制造工艺
US20240039514A1 (en) * 2021-04-16 2024-02-01 Murata Manufacturing Co., Ltd. Acoustic wave device
CN117824824A (zh) * 2023-12-05 2024-04-05 南京航空航天大学 一种具有沟槽形支撑层的fbar传感器

Families Citing this family (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5128077B2 (ja) * 2006-02-21 2013-01-23 宇部興産株式会社 薄膜圧電共振器とそれを用いた薄膜圧電フィルタ
JP5027534B2 (ja) * 2006-07-07 2012-09-19 日本碍子株式会社 圧電薄膜デバイス
JP2008109402A (ja) * 2006-10-25 2008-05-08 Toshiba Corp 薄膜圧電共振器およびその製造方法
US20100194246A1 (en) * 2009-01-30 2010-08-05 Integrated Device Technology, Inc. Thin-Film Bulk Acoustic Resonators Having Reduced Susceptibility to Process-Induced Material Thickness Variations
US8291559B2 (en) * 2009-02-24 2012-10-23 Epcos Ag Process for adapting resonance frequency of a BAW resonator
US9154107B2 (en) * 2009-05-28 2015-10-06 Northrop Grumman Systems Corporation Lateral over-moded bulk acoustic resonators
JP2011041136A (ja) * 2009-08-17 2011-02-24 Taiyo Yuden Co Ltd 弾性波デバイスおよびその製造方法
US8330556B2 (en) * 2009-11-23 2012-12-11 Avago Technologies Wireless Ip (Singapore) Pte. Ltd. Passivation layers in acoustic resonators
JP5229308B2 (ja) * 2010-12-07 2013-07-03 株式会社村田製作所 圧電デバイス及びその製造方法
US8816567B2 (en) * 2011-07-19 2014-08-26 Qualcomm Mems Technologies, Inc. Piezoelectric laterally vibrating resonator structure geometries for spurious frequency suppression
US8922302B2 (en) 2011-08-24 2014-12-30 Avago Technologies General Ip (Singapore) Pte. Ltd. Acoustic resonator formed on a pedestal
US9793874B2 (en) * 2014-05-28 2017-10-17 Avago Technologies General Ip Singapore (Singapore) Pte. Ltd. Acoustic resonator with electrical interconnect disposed in underlying dielectric
US10038422B2 (en) 2016-08-25 2018-07-31 Qualcomm Incorporated Single-chip multi-frequency film bulk acoustic-wave resonators
TWI611604B (zh) * 2017-01-03 2018-01-11 穩懋半導體股份有限公司 體聲波濾波器及調諧體聲波濾波器之體聲波共振器之方法
JP6545772B2 (ja) * 2017-01-03 2019-07-17 ウィン セミコンダクターズ コーポレーション 質量調整構造付きバルク音響波共振装置の製造方法
JP6909059B2 (ja) * 2017-06-07 2021-07-28 太陽誘電株式会社 圧電薄膜共振器、フィルタおよびマルチプレクサ
CN110445474B (zh) * 2018-05-04 2024-08-16 苏州汉天下电子有限公司 薄膜体声波谐振器及其制造方法以及薄膜体声波滤波器
US10790801B2 (en) 2018-09-07 2020-09-29 Vtt Technical Research Centre Of Finland Ltd Loaded resonators for adjusting frequency response of acoustic wave resonators
CN111010103A (zh) * 2019-05-31 2020-04-14 天津大学 带多层突起结构的谐振器及其制造方法、滤波器及电子设备
CN112087217B (zh) * 2020-09-27 2024-02-23 苏州汉天下电子有限公司 Q值提升的fbar谐振器制造方法
KR102609139B1 (ko) 2020-10-13 2023-12-05 삼성전기주식회사 체적 음향 공진기

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5873153A (en) * 1993-12-21 1999-02-23 Hewlett-Packard Company Method of making tunable thin film acoustic resonators
US6469597B2 (en) * 2001-03-05 2002-10-22 Agilent Technologies, Inc. Method of mass loading of thin film bulk acoustic resonators (FBAR) for creating resonators of different frequencies and apparatus embodying the method
US6483229B2 (en) * 2001-03-05 2002-11-19 Agilent Technologies, Inc. Method of providing differential frequency adjusts in a thin film bulk acoustic resonator (FBAR) filter and apparatus embodying the method
US6617249B2 (en) * 2001-03-05 2003-09-09 Agilent Technologies, Inc. Method for making thin film bulk acoustic resonators (FBARS) with different frequencies on a single substrate and apparatus embodying the method
US6992420B2 (en) * 2002-04-11 2006-01-31 Samsung Electro-Mechanics Co., Ltd. Film bulk acoustic resonator and method of forming the same

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3715831B2 (ja) * 1999-05-24 2005-11-16 京セラ株式会社 圧電共振子
JP4513169B2 (ja) * 2000-05-17 2010-07-28 株式会社村田製作所 圧電フィルタ、通信装置および圧電フィルタの製造方法
US6407649B1 (en) * 2001-01-05 2002-06-18 Nokia Corporation Monolithic FBAR duplexer and method of making the same
US6936837B2 (en) * 2001-05-11 2005-08-30 Ube Industries, Ltd. Film bulk acoustic resonator
JP2002344280A (ja) * 2001-05-18 2002-11-29 Mitsubishi Electric Corp 圧電薄膜素子とその製造方法
JP2003264445A (ja) * 2002-03-08 2003-09-19 Murata Mfg Co Ltd 圧電共振子及びその製造方法等、並びに圧電フィルタ等
JP3830843B2 (ja) * 2002-03-28 2006-10-11 株式会社東芝 薄膜圧電共振子
KR100506729B1 (ko) * 2002-05-21 2005-08-08 삼성전기주식회사 박막 벌크 어코스틱 공진기（ＦＢＡＲｓ）소자 및 그제조방법
DE60336567D1 (de) * 2002-06-20 2011-05-12 Ube Industries Piezoelektrischer d nnfilmoszillator, piezoelektrisches d nnfilmbauelement und herstellungsverfahren daf r

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5873153A (en) * 1993-12-21 1999-02-23 Hewlett-Packard Company Method of making tunable thin film acoustic resonators
US6469597B2 (en) * 2001-03-05 2002-10-22 Agilent Technologies, Inc. Method of mass loading of thin film bulk acoustic resonators (FBAR) for creating resonators of different frequencies and apparatus embodying the method
US6483229B2 (en) * 2001-03-05 2002-11-19 Agilent Technologies, Inc. Method of providing differential frequency adjusts in a thin film bulk acoustic resonator (FBAR) filter and apparatus embodying the method
US6617249B2 (en) * 2001-03-05 2003-09-09 Agilent Technologies, Inc. Method for making thin film bulk acoustic resonators (FBARS) with different frequencies on a single substrate and apparatus embodying the method
US6992420B2 (en) * 2002-04-11 2006-01-31 Samsung Electro-Mechanics Co., Ltd. Film bulk acoustic resonator and method of forming the same

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050099092A1 (en) * 2003-11-07 2005-05-12 Hiroyuki Nakamura Piezoelectric device, antenna duplexer, and method of manufacturing piezoelectric resonators used therefor
US7242130B2 (en) * 2003-11-07 2007-07-10 Matsushita Electric Industrial Co., Ltd. Piezoelectric device, antenna duplexer, and method of manufacturing piezoelectric resonators used therefor
US20100052476A1 (en) * 2007-11-21 2010-03-04 Panasonic Corporation Piezoelectric filter and method for manufacturing the same
US8049581B2 (en) 2007-11-21 2011-11-01 Panasonic Corporation Piezoelectric filter and method for manufacturing the same
US20160339475A1 (en) * 2015-05-20 2016-11-24 uBeam Inc. Transducer array subdicing
US10233076B2 (en) * 2015-05-20 2019-03-19 uBeam Inc. Transducer array subdicing
CN111293101A (zh) * 2018-12-10 2020-06-16 新光电气工业株式会社 半导体封装
CN109889174A (zh) * 2019-02-20 2019-06-14 中国科学院微电子研究所 一种谐振器及其制作方法
US12255628B2 (en) * 2019-09-27 2025-03-18 Murata Manufacturing Co., Ltd. Acoustic wave device
US20220216854A1 (en) * 2019-09-27 2022-07-07 Murata Manufacturing Co., Ltd. Acoustic wave device
WO2021114970A1 (zh) * 2019-12-11 2021-06-17 苏州汉天下电子有限公司 一种薄膜体声波谐振器结构及其制造方法、滤波器以及双工器
CN111130486A (zh) * 2019-12-11 2020-05-08 北京汉天下微电子有限公司 一种薄膜体声波谐振器结构及其制造方法、滤波器以及双工器
CN111082777A (zh) * 2019-12-31 2020-04-28 诺思(天津)微系统有限责任公司 底电极为空隙电极的体声波谐振器、滤波器及电子设备
CN111277240A (zh) * 2020-03-07 2020-06-12 中国电子科技集团公司第二十六研究所 一种薄膜体声波滤波器的膜层结构及其制备方法
WO2022052915A1 (zh) * 2020-09-09 2022-03-17 诺思(天津)微系统有限责任公司 滤波器组件及其制造方法、电子设备
CN114244300A (zh) * 2020-09-09 2022-03-25 诺思(天津)微系统有限责任公司 滤波器组件及其制造方法、电子设备
CN112601169A (zh) * 2020-12-15 2021-04-02 武汉大学 一种宽频带高灵敏度谐振式压电mems麦克风
CN112886940A (zh) * 2021-01-13 2021-06-01 武汉大学 一种易于集成的fbar滤波器
US20240039514A1 (en) * 2021-04-16 2024-02-01 Murata Manufacturing Co., Ltd. Acoustic wave device
CN113612463A (zh) * 2021-06-30 2021-11-05 中国电子科技集团公司第十三研究所 阶梯型薄膜体声波谐振器滤波器及滤波器组件
CN114160399A (zh) * 2021-12-02 2022-03-11 中国科学院苏州纳米技术与纳米仿生研究所 同频异构的压电超声波换能器及其制备方法
CN116248068A (zh) * 2022-09-28 2023-06-09 泰晶科技股份有限公司 一种超高频at切石英晶片及制造工艺
CN117824824A (zh) * 2023-12-05 2024-04-05 南京航空航天大学 一种具有沟槽形支撑层的fbar传感器

Also Published As

Publication number Publication date
JP4625260B2 (ja) 2011-02-02
US7408287B2 (en) 2008-08-05
US20070069606A1 (en) 2007-03-29
JP2005223479A (ja) 2005-08-18

Similar Documents

Publication Publication Date Title
US7408287B2 (en) Film bulk acoustic wave resonator, film bulk acoustic wave resonator filter and method of manufacturing film bulk acoustic wave resonator
US7586390B2 (en) Bulk acoustic wave resonator, bulk acoustic wave filter, RF module including bulk acoustic wave resonator and/or filter, and bulk acoustic wave oscillator
US7986075B2 (en) Film bulk acoustic wave resonator, its fabrication method and film bulk acoustic wave resonator filter using the resonator
US10784838B2 (en) Air-gap type film bulk acoustic resonator and method of manufacturing the same
KR100622955B1 (ko) 박막 벌크 음향 공진기 및 그 제조방법
JP4654220B2 (ja) 圧電共振子を含むフィルタ構造
KR100771345B1 (ko) 압전 박막 공진자 및 필터
US20080169728A1 (en) Piezoelectric thin film resonator, piezoelectric thin film resonator filter and manufacturing method thereof
US8941450B2 (en) Acoustic wave device having a frequency control film
US20040021400A1 (en) Resonator with seed layer
US6741146B2 (en) Filter structure comprising piezoelectric resonators
US8749320B2 (en) Acoustic wave device and method for manufacturing the same
US10658998B2 (en) Piezoelectric film transfer for acoustic resonators and filters
CN101741343A (zh) 谐振器、滤波器、以及电子装置
US20070126527A1 (en) System on chip structure comprising air cavity for isolating elements, duplexer, and duplexer fabrication method thereof
US6894360B2 (en) Electrostatic discharge protection of thin-film resonators
US20040021529A1 (en) Resonator with protective layer
US8344590B2 (en) Acoustic wave device with frequency control film
KR100555762B1 (ko) 에어갭형 박막 벌크 음향 공진기 및 그 제조방법, 이를이용한 필터 및 듀플렉서
US7242130B2 (en) Piezoelectric device, antenna duplexer, and method of manufacturing piezoelectric resonators used therefor
CN112398459A (zh) 气隙式膜体声谐振器
JP2017041709A (ja) 弾性波フィルタ、分波器、及びモジュール
US7113055B2 (en) Piezoelectric resonator, method of manufacturing piezoelectric resonator, and filter, duplexer, and communication device using piezoelectric resonator
TW202324921A (zh) 體聲波共振器濾波器以及體聲波共振器濾波器模組
CN115085689A (zh) 气隙式fbar

Legal Events

Date Code Title Description
AS Assignment

Owner name: HITACHI MEDIA ELECTRONICS CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:MATSUMOTO, HISANORI;ASAI, KENGO;ISOBE, ATSUSHI;AND OTHERS;REEL/FRAME:015652/0457;SIGNING DATES FROM 20040713 TO 20040714

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION